* FTSEurofirst 300 index falls 0.5 percent
* Tech shares down 1.6 pct, tracks Nasdaq sell-off
* Charts signal further weakness in near term
European shares extended losses on Monday, with a major index slipping to its lowest level in three weeks, as fresh tension in Ukraine prompted investors to shun cyclical sectors such as travel, autos and technology.
Charts also pointed to a bearish outlook in the near term and the broader market remained vulnerable to further sell-offs, technical analysts said.
The pan-European FTSEurofirst 300 index was down 0.5 percent at 1,305.78 points by 1017 GMT, after falling as low as 1,301.98, its weakest since late March. The index fell 3 percent last week, and analysts said the trouble in Ukraine could prevent it from bouncing back anytime soon.
Cyclicals lost ground, with the STOXX Europe 600 Travel and Leisure index down 2.3 percent, tech shares falling 1.9 percent and autos down 1.8 percent.
However, losses were capped by a rise in some defensive sectors, such as personal and household goods and food and beverages, which were up more than 1 percent.
"Geopolitical concerns are putting pressure on equities," said Christian Stocker, an equity strategist at UniCredit in Munich. "Markets fear an escalation in tension will result in more economic sanctions on Russia and that will have a negative repercussion on Europe."
Ukraine gave pro-Russian separatists a deadline to disarm or face a "full-scale anti-terrorist operation". The UN's Security Council met in emergency session.
Several firms exposed to Russia fell. Finnish tyre maker Nokian Renkaat, Austrian lender Raiffeisen Bank International, UniCredit, Italy's biggest bank by assets, and Belgian financial group KBC lost from 1.8 to 3.5 percent.
Nokian Renkaat, Raiffeisen, UniCredit and KBC get 14 to 26 percent of their revenues from Russia. For a factbox on European firms most exposed to Russia, click on
Germany's benchmark DAX index, which includes several companies with significant exposure to Russia, lagged the wider market, falling 0.7 percent.
The euro zone's blue chip Euro STOXX 50 index declined 0.7 percent to 3,094.87 points, with charts signalling that the index could fall further.
"Although the slope of the 200-day moving average remains up at this juncture, the Euro STOXX 50 index has turned down from the up-channel resistance line stretching back to 2011 and the move below support around 3,150 is another worry for bulls," said Murray Gunn, the head of technical analysis at HSBC.
The index could find support around 2,971 points. On the upside, 3,196 is considered a strong resistance level.
Among sectors, the STOXX Europe 600 tech index fell 1.6 percent, taking its losses since early April to more than 6 percent on concern that valuations have become stretched.
Tech stocks are the most expensive in Europe, according to Thomson Reuters Datastream. They trade at around 19 times their 12-month forward earnings, against a 10-year average of about 16 times and the STOXX 600's price-earnings ratio of 14.
Ericsson fell 4.2 percent and ARM Holdings 2.2 percent, mirroring losses on the Nasdaq, which ended on Friday below 4,000 for the first time since early February.
Among other sharp movers, Greece's largest lender, National Bank, fell 14 percent, making it the biggest decliner on the FTSEurofirst 300. A banker told Reuters on Saturday the bank might tap international markets with a share offering as part of plans to plug a capital shortfall.
Despite recent jitters on Wall Street and simmering tensions in Ukraine, investors have continued to pour money into European equities. They attracted more than $1 billion in the week ended April 9, according to EPFR Global data.